The production of artificial reverberation has been achieved in many ways for electronic organs and other electrical musical instruments and for phonographs, audio amplifiers and other devices in which the introduction of reverberation is desirable to simulate, in the reproduced sound, the acoustics found in a large music hall. In general, the artificial electro-mechanical reverberation devices used to date have incorporated a driver, one or more torsionally driven springs and a pickup (separate from the driver) driven by the torsionally vibrating springs to produce an output signal which includes the original signal plus a multitude of delayed signals arising from that phase shifting and time delay of the original signal caused by torsional vibrations in the one or more springs of the system.
With advances in printed circuits and in other components of electronic apparatus the size of such apparatus has become dramatically smaller. However, the size of associated reverberation apparatus has not been significantly reduced up to the time of this invention. Further, cost has become an increasingly vital factor in electronic audio amplifiers and the use of separate transducers, which has been necessary prior to this invention, has prevented significant cost reductions in reverberation apparatus for audio systems. The use of separate input and output transducers has been dictated by the need to achieve a reasonable level of reflected signal relative to original signal (or rejection of the original signal) in the output composite signal from the reverberation unit.
Therefore, it is an object of the present invention to overcome in an electro-mechanical, artificial reverberation system, the problems and disadvantages set forth hereinbefore.
It is a still further object of the present invention to provide a compact, low-cost artificial reverberation unit.
It is an additional object of this invention to provide an artificial reverberation unit in which a single transducer at one end of the unit of reduced length provides the reverberation effects previously achievable only with a larger unit having separate input and output transducers.